Background: Extrahepatic biliary duct cancers (EBDC) are uncommon malignancies characterized by a poor prognosis with high rate of loco-regional recurrence. The purpose of the present study is to assess the feasibility and the potential impact of adjuvant radiotherapy (RT) in a series of patients treated in one institution. Methods: Twenty three patients with non-metastatic bile duct cancer treated surgically with curative intent (4 gallbladder, 7 ampullary and 12 cholangiocarcinoma) received 3D conformal external beam RT to a median total dose of 50.4Gy. Concurrent chemotherapy based on 5-FU was delivered to 21 patients (91%). Surgical margins were negative in 11 patients (48%), narrow in 2 (9%), and microscopically involved in 8 (35%). Eleven patients (55%) had metastatic nodal involvement. The average follow-up time for all patients was 30 months (ranging from 3-98). Results: Acute gastrointestinal grade 2 toxicity (RTOG scale) was recorded in 2 patients (9%). Nausea or vomiting grade 1 and 2 was observed in 8 (35%) and 2 patients (9%) respectively. Only one patient developed a major late radiation-induced toxicity. The main pattern of recurrence was both loco-regional and distant (liver, peritoneum and/or lung). No difference was observed in loco-regional control according to the tumor location. The 5-year actuarial loco-regional control rate was 48.3% (67% and 30% for patients operated on with negative and positive/narrow/unknown margins respectively, p = 0.04). The 5-year actuarial overall survival was of 35.9% for the entire group (61.4% in case of negative margins and 16.7% in case of positive/narrow/unknown margins, p = 0.07). Conclusions: Postoperative RT with 50-60 Gy is feasible with acceptable acute and late toxicities. The potential benefit observed in our series may support the use of adjuvant RT in patients with locally advanced disease. Prospective randomized trials are warranted to confirm definitively the role of RT in this tumor location.